1. Field of the Invention
The present invention relates to a method for fire rescue navigation, and more particularly relates to a method of using light striping to provide illumination and navigation in smoke-filled structures.
2. Description of the Prior Art
Visibility inside a burning building is very limited because of heavy smoke or flame. When a building is on fire, firefighters have to enter various parts of the building for emergency rescue, but because of poor visibility in the smoke-filled building, the firefighters may become disorientated and may be unable to find exits or notice holes or damages in the floor, which is very dangerous and also makes it hard to implement effective rescue. So smoke area lighting is a critical problem for fire rescue. The typical practice is to place a flashlight at the exit, with the beam of the flashlight pointing in the direction from which the firefighter expects to exit later. However, the flashlight beam usually does not penetrate very far. This is because the flashlight emits white or incoherent light. The full spectrum light illuminates the smoke molecules which reflect the light, thereby reducing penetration of the flashlight beam through the smoke and also causing blinding light to occur.
Coherent light such as a laser beam can penetrate smoke areas without the blinding reflection of commonly used flashlight sources and thus be considered as a distinguished lighting source for use in smoke-filled structures. But a single laser beam still cannot achieve a satisfactory lighting effect for fire rescue since a single laser beam is simply a point when projected on an object. Meanwhile, using multiple lasers would be an issue as each laser requires power supply and heat dissipation, and thus would increase the power consumption and the limitation of the operating environment. Therefore, a new technique is desirable to use a single laser source to produce multiple beams of coherent light, one or more light planes for illumination and navigation in smoke-filled structures.
In addition, prior arts of using a light striping method to reconstruct a 3D dimensional form of an object have existed since the 1980's in the field of 3D measurements. A light striping vision system uses one or more light stripes projected onto a 3D object by a line laser source to detect the image coordinates of the light stripes and obtain 3D coordinates of the surface points of an object. The line laser source generates one or more coherent light planes that can create a 3D visual effect when illuminating an indoor space. So it can be conceived to utilize a similar light striping vision system to provide illumination and navigation for fire rescue.
The conventional light striping vision system has never been envisioned for fire rescue navigation and never been designed as a portable device that can be easily carried and directly controlled by a human being. In this respect, the laser lighting apparatus and method for fire rescue navigation of the current invention substantially departs from the conventional design of light striping vision systems for 3D object measurements, and is aimed at providing an improved lighting apparatus and method for illumination and navigation in smoke-filled structures.